UKPN to install its first SF6-free gas insulated switchgearUKPN to install its first SF6-free gas insulated switchgear

Distribution network operator (DNO) UK Power Networks (UKPN) is installing its first sulphur hexafluoride (SF6) free, ‘clean air’ gas insulated switchgear (GIS).

The GIS will operate at 132,000-volts and is to be installed as part of a substation upgrade in Lewes, East Sussex.

Various members of the energy sector have called for reduced use of SF6 with National Grid having previously stated that it has a global warming potential that is 25,200 times greater than CO2.

SF6 had traditionally been used to help create the UK power network we all know today. The gas is a highly efficient electrical insulator, and this can be utilised within various applications such as medium and high-voltage switchgear and circuit breakers.

UKPN has recognised the damage harnessing SF6 can have on the environment and thus is striving to reduce the use of SF6 for new switchgear across all voltage ranges when alternatives on the market are available.

The DNO has also established a net zero target by 2028 on its controllable Scope 1 and 2 emissions with SF6 included within this.

The SF6-free technology, which has been supplied by Siemens Energy, is composed of dehumidified oxygen and nitrogen significantly reducing the carbon footprint of the GIS technology.

You can find out more information on the installation of the technology below:

“Switchgear plays a vital role in the safe and secure distribution of electricity to homes and businesses. Over time, we want to make more use of environmentally-friendly technology to support a net zero carbon future,” said Barry Hatton, director of asset management at UK Power Networks.

“This investment will pave the way for minimising the volume of SF6 on our network and using alternatives which maintain reliability and performance. We want to continue embracing innovative, sustainable and smart approaches to help enable the low carbon transition and minimise our own carbon footprint.”

National Grid has been showcasing SF6-free technology in a range of projects which have been covered on Current± over the course of the previous year.

The first project to note is National Grid’s £1 billion London grid upgrade which was set to implement SF6-free technologies to reduce the carbon footprint of the project.

Construction engineering company Linxon is building the Bengeworth Road substation for National Grid. Hitachi Energy will deliver EconiQ 400kV gas-insulated switchgear and gas-insulated lines containing no SF6 helping to reduce the emissions of the substation and LPT project.

National Grid has also been exploring the creation of a retrofill solution to remove SF6 across its network of high-voltage equipment in partnership with the University of Manchester.

The two organisations announced they were to collaborate on the creation of a retrofill solution to replace SF6 with an environmentally friendlier alternative without having to replace or otherwise modify the existing equipment.

The University of Manchester and National Grid are aiming to create a physical demonstration with an inbuilt condition-based monitoring system that will focus on the applicability of SF6 retrofill techniques.

These two developments form part of National Grid’s plan to reduce SF6 emissions by 50% by 2030 ahead of its full removal by 2050.